The invention relates to sewing machines in general, and more particularly to improvements in apparatus which can be used in sewing machines to guide and brake elastic or other bands during sewing of such bands to pieces of fabric or like commodities.
When a band, especially an elastic band, is to be sewn to a garment so that a portion of the garment is ruffled or gathered as a result of attachment of the band thereto, it is necessary to maintain the band under tension so that the band can contract when the sewing operation is completed and thus provides the adjacent portion of the garment with ruffles. The thus attached band can form part of the waistband of a skirt, the waistband of pajama slacks or the like.
It is already known to guide and brake a band or tape, such as an elastic band, in commercially used sewing machines so that the band is under tension during sewing to a piece of fabric or a like commodity. For example, Swiss Pat. No. 500,314 discloses an apparatus which is designed to feed elastic bands from a source adjacent the sewing machine into a funnel-shaped guide which is mounted on a pivotable arm adjacent to the locus of penetration of the needle into the band and into the piece of fabric to be connected with the band. The band is deflected through an angle of 90 degrees on its way from the source toward the funnel. Such band feeding apparatus is associated with a severing device which can cut across the band upon completion of the sewing operation. A drawback of the patented apparatus is its excessive cost and bulk. Therefore, such apparatus cannot be readily installed in or used in conjunction with a household sewing machine for occasional sewing of elastic or like bands to garments or like commodities. Furthermore, installation of such apparatus in a conventional sewing machine would necessitate extensive modifications of the machine.
Other types of apparatus for supplying bands to commercial sewing machines are disclosed in German Pat. No. 34 10 181 and in U.S. Pat. No. 4,649,839. The patented apparatus are not suitable for occasional use in household sewing machines.
Swiss Pat. No. 625 279 discloses an apparatus which can be used, as a means for tensioning elastic bands which are to be sewn to garments or like commodities in a household sewing machine. The patented apparatus comprises two plates which are connected to each other so as to define a passage of unvariable cross-sectional area. The band to be sewn in threaded through the passage and is acted upon by a plate-like biasing member which is movably mounted on the upper of the two plates and can be raised or lowered by a screw so as to bear against the upper side of the band with a selected braking and stretching force. A leaf spring is installed between the biasing member and the upper plate in order to lift the biasing member above and away from the band in the passage as soon as such upward movement is permitted by the screw. The patent proposes to employ two studs which are to be inserted into bores adjacent the locus of penetration of the needle into the band. The bores must be drilled into the frame of a sewing machine for the express purpose of receiving the studs. When the apparatus is installed in a sewing machine and the operator wishes to change the bias of the plate-like member upon the band in the passage, it is necessary to employ a screw driver or another tool which is manipulated to turn the screw and to thus move the biasing member upwardly away from or downwardly toward the band. The width of the passage is fixed so that the patented apparatus can be used only for the sewing of bands having a predetermined width. If a narrower band is to be sewn to a piece of fabric or the like, such narrower band must be guided by hand which is highly unlikely to result in attachment of the band in an eye-pleasing manner. Alternatively, it is necessary to furnish a plurality of apparatus each of which has a passage of a given width.